How to build shared library on Linux

[gbook]

I'm attempting to build my program, which uses bit7z, as a shared library on CentOS 8. I'm able to build it successfully as a command line application, but when building it as a library, I get link errors related to bit7z.

A few dozen errors like this:

...
/usr/bin/ld: ../../bit7z/lib/x64/libbit7z64.a(bit7zlibrary.cpp.o): relocation R_X86_64_32 against `.rodata.str1.1' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: ../../bit7z/lib/x64/libbit7z64.a(bitabstractarchivecreator.cpp.o): relocation R_X86_64_32S against `.rodata' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: ../../bit7z/lib/x64/libbit7z64.a(bitabstractarchivehandler.cpp.o): relocation R_X86_64_32S against symbol `_ZTVN5bit7z25BitAbstractArchiveHandlerE' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: ../../bit7z/lib/x64/libbit7z64.a(bitabstractarchiveopener.cpp.o): relocation R_X86_64_32S against symbol `_ZTVN5bit7z24BitAbstractArchiveOpenerE' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: ../../bit7z/lib/x64/libbit7z64.a(bitarchiveeditor.cpp.o): relocation R_X86_64_32 against `.rodata.str1.8' can not be used when making a shared object; recompile with -fPIC
...

The error seems to be because the linker is expecting a shared library (*.so) and I'm giving it a static library (*.a). I can't seem to build bit7z as a shared library though on Linux.

Is there a way to build bit7z as a shared library?

[gbook]

Fixed it by setting the following flags:
CMAKE_CXX_FLAGS to -fPIC
CMAKE_C_FLAGS to -fPIC